Push button starting system for outdoor power equipment

ABSTRACT

A starting system for outdoor power equipment that has a controller and a start button to control the activation of an internal combustion engine. The starting system includes a controller that receives a start signal from a start button. The controller monitors for the presence of an enable device in an enable device receptacle and, upon activation of the start button and the presence of the enable device in the enable device receptacle, the controller provides electric power to the electric load of the power equipment. When the start button is depressed for longer than a minimum engagement period, the controller initiates operation of the engine. If the start button is pressed for less than the minimum engagement period, the controller activates the electric load for an auxiliary period without starting the engine. During engine operation, if the start button is depressed, the controller terminates operation of the engine.

BACKGROUND OF THE INVENTION

The present disclosure generally relates to a starting system for aninternal combustion engine. More specifically, the present disclosurerelates to a push button starting system for the internal combustionengine of a piece of outdoor power equipment, such as a lawn tractor,walk behind mower, pressure washer, portable electric generator, snowblower or the like. The push button starting system requires both thepresence of an enable device, such as a key fob, and depression of astart button to begin operation of the internal combustion engine.

Currently available outdoor power equipment, such as lawn tractors, walkbehind mowers and the like, include an internal combustion engine thatprovides both the motive force for the power equipment and the requiredpower to rotate a cutting blade. Typically, the internal combustionengine of the power equipment, such as a lawn tractor, is started byinserting a key into an ignition switch. Once the key is inserted intothe ignition switch, the key is turned to crank the internal combustionengine. Typically, the key remains in the cranking position until theengine turns over and begins running. Once the engine has started, theoperator releases the key from the cranking position and the enginecontinues operation.

Although an ignition switch and key have been a successful way to startthe internal combustion engine of a lawn tractor for many years,drawbacks exist for inexperienced users who may not feel comfortablewith the procedures required to start the internal combustion engine. Asan example, many inexperienced users are unclear as to how long theengine needs to crank when the engine is initially slow to start.

In addition to the drawbacks set forth above, lawn tractors that includean ignition switch and key may allow the operator to turn the keypartially toward the cranking position. In this intermediate, auxiliaryposition, electric power from the vehicle battery is supplied to theelectronics load of the lawn tractor, such as the headlights and otherelectrical components contained on the lawn tractor. The use of theauxiliary position is particularly beneficial when the operator does notwant to start the engine but simply wants to operate the electricalcomponents contained on the tractor. Although the auxiliary position isbeneficial, if the ignition key is left in the auxiliary position for anextended period of time, the electric load will eventually drain thebattery of the lawn tractor, thus rendering the lawn tractor inoperablewithout either replacing or recharging the battery.

SUMMARY OF THE DISCLOSURE

The present disclosure provides a push button starting system for theinternal combustion engine of outdoor power equipment, such as but notlimited to a lawn tractor. The push button starting system requires boththe presence of an enable device in an enable device receptacle anddepression of a start button to begin operation of the internalcombustion engine. The push button starting system of the presentdisclosure includes a controller that controls operation of manycomponents of the lawn tractor, including the starting of the internalcombustion of the lawn tractor. The controller initiates operation ofthe internal combustion engine of the lawn tractor by closing thecontacts of a starter solenoid relay to crank the engine.

A start button is connected to the controller and generates a startsignal sensed by the controller when the start press button is in theactivated position. In one embodiment of the disclosure, the startbutton is a push button that is activated by depressing and holding thepush button. The controller receives the start signal during the entiretime the start button is in the activated state.

When the controller receives the start signal, the controller awakensfrom a sleep mode and checks to determine whether an enable device is inan enable device receptacle of the lawn tractor. If the enable device isnot in the enable device receptacle, the controller returns to thesleeping mode.

If the controller determines that the enable device is in the enabledevice receptacle after receiving the start signal, the controllerenergizes a load relay which provides electric power to the electricload of the lawn tractor. After the load relay is energized, thecontroller starts an auxiliary period timer. The controller provideselectric power to the electric load of the lawn tractor for only anauxiliary period. In one embodiment of the disclosure, the auxiliaryperiod is two minutes. In this manner, the operator can power theelectric load of the lawn tractor by depressing and releasing the startbutton.

The controller then determines if the start signal was received forgreater than a minimum engagement period. If the start signal wasreceived for less than the minimum engagement period, the controllercontinues the auxiliary period timer and eventually de-energizes theload relay after the expiration of the auxiliary period.

If the controller senses the start signal for greater than the minimumengagement period, the controller determines whether an operator ispresent in the seat of the lawn tractor. If the operator is present inthe seat, the controller can initiate operation of the internalcombustion engine. However, if an operator is not present in the seat ofthe lawn tractor, operation of the internal combustion engine isdelayed.

If the controller receives the start signal for greater than the minimumengagement period, determines that that enable device is present in theenable device receptacle and detects the presence of an operator in theseat of the lawn tractor, the controller closes the contacts of astarter solenoid relay which initiates operation of the internalcombustion engine. Once the internal combustion engine has started, thecontroller then monitors for the presence of the start signal due to asubsequent depression of the start button. Once the controller detectsthe presence of the start signal, the controller opens the contacts ofan ignition short relay to interrupt operation of the internalcombustion engine.

In the push button starting system of the present disclosure, thecontroller can control operation of the electric load and startersolenoid only when the enable device is within the enable devicereceptacle. If the enable device is removed from the enable devicereceptacle, the enable device receptacle overrides the controller andprevents activation of the internal combustion engine. In this manner,the push button starting system of the present disclosure requires theenable device to be in the enable device receptacle and depression ofthe start button before the controller initiates operation of theinternal combustion engine.

Various other features, objects and advantages of the invention will bemade apparent from the following description taken together with thedrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings illustrate the best mode presently contemplated of carryingout the invention. In the drawings:

FIG. 1 is a perspective view of a lawn tractor including the push buttonstarting system of the present disclosure;

FIG. 2 is a magnified view of the dashboard of the lawn tractorincluding the push button starting system of the present disclosure;

FIG. 3 is an electronic schematic illustration of the push buttonstarting system of the present disclosure; and

FIG. 4 is a flowchart illustrating one possible sequence of operation ofthe push-button starting system of the present disclosure.

DETAILED DESCRIPTION OF THE DRAWINGS

The present disclosure is directed to a starting system for an internalcombustion engine of outdoor power equipment, such as but not limited toa lawn tractor, walk-behind mower, pressure washer, portable electricgenerator, snow blower or other similar type of equipment. The drawingsfigures depict the use of the starting system with one type ofequipment, namely a lawn tractor. However, it should be understood thatthe starting system could be utilized with other types of outdoor powerequipment while falling within the scope of the disclosure and theclaims.

FIG. 1 illustrates a riding lawn tractor 10 that typically includes amowing assembly 11 mounted beneath a vehicle chassis 12 supported byfour wheels 14. The lawn tractor 10 includes an internal combustionengine (not shown) that powers both the rear drive wheels and a mowerblade contained within the mowing assembly 11. A steering wheel 16allows an operator positioned in the seat 18 to control the movement ofthe lawn tractor 10, as is conventional. The details of the lawn tractor10 shown in FIG. 1 are meant for illustrative purposes only since thelawn tractor 10 could have various different operator controls andphysical configurations while falling within the scope of the presentdisclosure.

FIG. 2 generally illustrates the dashboard 20 visible to the operatorwhen the operator is in the seated position. The dashboard 20 includesthe steering wheel 16, a speed selection handle 22, an enable devicereceptacle 24, a start button 26 and a display panel 28. Although theseoperating components are shown included on the dashboard 20, it shouldbe understood that various other components could be utilized whileoperating within the scope of the present disclosure.

As illustrated in FIG. 2, the enable device receptacle 24 receives anenable device 30. The enable device 30 can be removed from the enabledevice receptacle 24 and carried with the operator when the lawn tractoris not in use. Removal of the enable device 30 from the enable devicereceptacle 24 will render the tractor inoperative, as will be describedbelow. In contemplated embodiments of the disclosure, the enable device30 could be any component that is received and detected by the enabledevice receptacle 24, such as a key fob received in a key fobreceptacle. Likewise, the enable device receptacle 24 could be any typeof receptacle that is capable of detecting the presence of the enabledevice 30. As an example, the enable device receptacle 24 could be asimple switch that moves from one position to another upon receipt ofthe enable device 30. Alternatively, the enable device 30 could includea magnetic section and the enable device receptacle 24 would detect thepresence of the magnetic section. Various other alternate embodimentsare contemplated as being within the scope of the present disclosure.

The display panel 28 is surrounded by six individual data entry buttons32 that can be selectively depressed by the operator to provide input tothe controller (not shown) used to operate the lawn tractor. As anexample, information can be presented on the display panel 28 and theoperator can depress one or more of the entry buttons 32 to provideinputs to the tractor controller.

In the embodiment shown in FIG. 2, the start button 26 is a push buttonhaving a visual indicator 34. The visual indicator 34 can be one ofseveral different components, but in the illustrated embodiment thevisual indicator 34 is an LED activated by the controller to indicatedepression of the start button 26, as will be described in greaterdetail below. In the embodiment illustrated, the start button 26 is apush button that can be depressed and held in an activated position bythe operator. The start button 26 is designed to allow the operator toinitiate operation of the internal combustion engine of the lawn tractorupon depressing and holding the start button 26.

FIG. 3 illustrates the electronic components and the configuration forthe starting system 36 of the present disclosure. As indicatedpreviously, the starting system 36 includes a controller 38. In theembodiment shown in FIG. 3, the controller 38 is a microcontroller, suchas and 8-bit 89LPC936, available from NXP Semiconductors. However, it iscontemplated that other types of controllers could be utilized whileoperating within the scope of the present disclosure.

The controller 38 includes a power input pin 40 that is connected to thestart button 26. The start button 26 is a normally open switch that isconnected between ground 42 and a transistor 44. When the normally openstart button 26 is activated, the start button 26 provides a path fromthe base of transistor 44 to ground. The ground connection provides astart signal to the controller 38 at the start button input pin 46. Thestart signal is provided at start button input pin 46 as long as thenormally open start button 26 remains in its closed, depressedcondition. The controller 38 monitors the duration of time the startsignal is provided on the start button input pin 46, as will bedescribed in greater detail below.

The controller 38 is further connected to the enable device receptacle24. As indicated above, the enable device receptacle 24 could be anormally closed switch. During the normally closed condition, the enabledevice receptacle 24 provides a connection from the enable device inputpin 48 to ground 42. When the enable device for the lawn tractor isinserted into the enable device receptacle 24, the normally closedenable device receptacle 24 opens, which is sensed by the controller 38through the enable device input pin 48.

In the embodiment illustrated in FIG. 3, the controller 38 is alsocoupled to a seat switch 50. The seat switch 50 is positioned beneaththe seat 18 of the lawn tractor 10, as shown in FIG. 1. When an operatoris present in the seat 18, the seat switch 50 opens. However, when anoperator is not present in the seat 18, the seat switch 50 remains inits normally closed condition. The status of the seat switch 50 can bedetermined on the seat check input pin 52.

The seat check input pin 52 is connected to a seat switch 50 through aseat check relay contacts 54. When the controller 38 desires to checkthe status of the seat switch, the controller 38 closes the seat checkrelay contacts 54. When the seat check relay contacts 54 are closed, thecontroller 38 can determine the status of the seat switch 50 through theseat check input pin 52.

The controller 38 includes a load output pin 56 that is coupled to aload relay 58 through a transistor 60. The load relay 58 includesnormally open load relay contacts 62 connected between the 12-volt powersupply 64 and the electrical load for the tractor present along outputline 66. When the controller 38 desires to energize the electrical loadfor the lawn tractor, the controller 38 generates a signal along theload output pin 56. If the enable device is in the enable devicereceptacle 24, the signal present at the load output pin 56 activatesthe transistor 60, which in turn closes the normally open load relaycontacts 62. However, if the enable device is not present in the enabledevice receptacle 24, the enable device receptacle 24 provides a path toground 42 from the base of transistor 60. Thus, the controller 38 canonly close the load relay contacts 62 when the enable device is in theenable device receptacle 24.

The controller further includes a starter solenoid output pin 68 that isconnected to a starter solenoid relay 70 through a transistor 72. Onceagain, if the enable device is not present in the enable devicereceptacle 24, the base of the transistor 72 is connected to ground andthe controller 38 cannot close the normally open starter solenoid relaycontacts 74. However, if the enable device is present within the enabledevice receptacle 24, the controller 38 can close the normally openstarter solenoid relay contacts 74 to provide power to the startersolenoid along output line 76.

Controller 38 further includes a seat check output pin 78 that isconnected to the seat check relay 80 through the transistor 82. Asdiscussed previously, when the enable device is not present within theenable device receptacle 24, the base of transistor 82 is grounded andthe controller 38 cannot activate the seat check relay 80. However, whenthe enable device is within the enable device receptacle 24, the outputsignal generated by the controller 38 on the seat check output pin 78causes the normally open seat check relay contacts 54 to move to aclosed position.

Finally, the controller 38 includes an ignition short output pin 84 thatis connected to an ignition short relay 86 through a transistor 88. Onceagain, when the enable device is not in the enable device receptacle 24,the base of transistor 88 is grounded through the enable devicereceptacle 24. However, when the enable device is inserted into theenable device receptacle 24, an output signal at the ignition shortoutput 84 activates the ignition short relay, which causes the normallyclosed ignition short relay contacts 90 to move to an open position.When the ignition short relay contacts are in an open position,operation of the internal combustion engine is allowed, and when closed,engine operation is terminated.

The circuit schematic of FIG. 3 is one embodiment of the presentdisclosure. However, it is contemplated that other embodiments could beutilized while operating within the scope of the present disclosure. Theactual operation of the controller will now be described with referenceto FIG. 4.

Since the controller 38 shown in FIG. 3 is operated from the 12-voltpower supply 64, it is desirable that the controller 38 remains in a“sleeping” mode during periods of non-use. It is particularly desirablethat the controller 38 remain in a sleeping mode even when the enabledevice is placed in the enable device receptacle 24, since it iscontemplated that many operators of the lawn tractor will allow theenable device to remain within the enable device receptacle 24 at alltimes.

As indicated in step 92, the controller 38 remains in the sleep modeuntil the controller 38 senses the depression of the start button 26, asindicated in step 94. When the controller 38 receives the start signalat the start button input pin 46, the controller 38 awakens andinitially determines whether the enable device is in the enable devicereceptacle 24, as illustrated in step 96. If the controller determinesin step 96 that the enable device is not present in the enable devicereceptacle, the controller returns to the sleep mode without everactivating the electric load for the lawn tractor. In this manner,activation of the electric load requires both the depression of thestart button 26 and the presence of the enable device within the enabledevice receptacle 24.

If the controller determines in step 96 that the enable device is in theenable device receptacle, the controller energizes the load relay 58 instep 98. To do so, the controller generates a high signal on the loadoutput pin 56, which in turn activates the transistor 60 and moves thenormally open load relay contacts 62 to the closed condition. Activationof the electric load allows the operator to use the tractor headlights,view the display and operate any other electric components of thetractor.

After the electric load for the tractor has been energized, thecontroller starts the auxiliary period timer in step 100. After theauxiliary period timer is started, the controller determines in step 102whether the start button 26 has been depressed for longer than a minimumengagement period. In one embodiment of the present disclosure, thecontroller 38 will not start the internal combustion engine unless thestart button is depressed for longer than the minimum engagement period.As an example, the minimum engagement period could be 0.5 seconds,although other time periods are contemplated. The use of a minimumengagement period prevents inadvertent depression of the start buttonfrom beginning operation of the internal combustion engine. However, itis contemplated that the minimum engagement period should have aduration sufficiently small to prevent the operator from having to holdthe start button in the depressed condition for an undesirably longperiod of time.

If the controller determines in step 102 that the start button wasdepressed for less than the minimum engagement period, the controllercontinues to count down the auxiliary period timer. The auxiliary periodtimer allows the controller to set an auxiliary period during which theelectric load is supplied with electric power from the lawn tractorbattery. In this manner, if the operator depresses the start button fora very brief period of time when the enable device is within the enabledevice receptacle, the controller 38 provides electric power to theelectric load of the tractor for the auxiliary period. In the currentlypreferred embodiment, the auxiliary period is approximately two minutes,although other periods of time are contemplated as being within thescope of the present disclosure.

In step 104, the controller 38 determines whether the two minuteauxiliary period has expired. If the auxiliary period has not expired,the timer continues to count until the auxiliary period has expired.Once the auxiliary period has expired, the controller de-energizes theload relay contacts 62, as illustrated in step 106. When the load relaycontacts are de-energized and opened, electric power is interrupted tothe electric load. After the electric power to the load is interrupted,the controller returns to the sleep mode, as illustrated in step 92. Inthis manner, the controller 38 provides electric power to the electricload, including the light for the lawn tractor, for the auxiliary periodafter the start button has been activated for less than the minimumengagement period. Thus, if the operator desires to operate the electricload of the tractor without actually initiating the engine operation,the operator can depress the start button 26 for less than the 0.5second minimum engagement period.

If the controller determines in step 102 that the start button wasdepressed for longer than the minimum engagement period, the controllerthen determines in step 108 whether the seat of the lawn tractor isoccupied. Referring back to FIG. 3, the controller 38 determines whetherthe seat is occupied by closing the seat check relay contacts 54. In theembodiment illustrated in FIG. 3, the controller only closes the seatcheck relay contacts when the controller 38 desires to determine thestatus of the seat switch 50.

If the controller determines in step 108 that the seat is not occupied,the controller determines whether the auxiliary period has expired, asillustrated in step 104. Since the controller 38 will not start theengine when the seat is unoccupied, the controller only activates theload relay 58 when the seat switch 50 is in the normally closedcondition.

In an embodiment in which the starting system is utilized with outdoorpower equipment other than a lawn tractor, the controller would not needto determine whether the seat is occupied. Instead, the controller couldbe configured to detect other conditions of the outdoor power equipment.As an illustrative example, if the starting system is used with awalk-behind mower, the controller would check on the position of acontact switch on the bail to ensure that the operator is away from theblade before cranking the engine. Similar conditions could be checkedwhen the starting system is used with a snow blower.

However, if the controller determines in step 108 that the seat isoccupied and the seat switch 50 is open, the controller 38 generates asignal to the starter solenoid relay 70, as illustrated in step 110. Thesignal to the starter solenoid relay 70 causes the normally open startersolenoid relay contacts 74 to close, thus providing electrical power tothe starter solenoid along output line 76. The output signal is suppliedto the starter solenoid until the engine begins operation. In step 112,the controller determines whether the engine has started. If the enginehas not started, the controller determines in step 114 whether thecranking period has been exceeded or whether the start button has beenreleased. As an example, the controller 38 will provide an output signalto the starter solenoid only for a maximum cranking period, such as 20seconds, or until the user releases the start button. If the engine doesnot begin operation during this cranking period, the system returns tomonitoring the start button and the auxiliary period timer in step 102.

If the controller determines in step 112 that the engine has started,the controller 38 terminates the signal to the starter solenoid relaycontacts, which opens the contacts and allows the internal combustionengine to run in a normal manner, as illustrated in step 116. Duringoperation of the internal combustion engine, the controller 38 continuesto monitor for whether the start button has been depressed, as indicatedin step 118. During normal operation of the internal combustion engine,if the start button 26 is depressed, this indicates that the operatorwishes to stop operation of the internal combustion engine. When thestart button is depressed in step 118, the controller 38 activates theignition short relay contacts 90, as illustrated in step 120. When theignition short relay contacts 90 are closed, operation of the internalcombustion engine is interrupted.

As can be understood by the above description, the presence of theenable device within the enable device receptacle 24 opens a connectionto ground. If the enable device is removed from the enable devicereceptacle 24, the removal of the enable device overrides the controller38 and prevents the controller 38 from changing the condition of theload relay contacts 62, the starter solenoid relay contacts 74 and theignition short relay contacts 90. Further, the removal of the enabledevice from the enable device receptacle 24 prevents the controller formclosing the seat check relay contacts 54. In this manner, the enabledevice is an override for the controller 38. Thus, the enable devicemust be present for the controller to initiate activation of theinternal combustion engine.

Although various contacts are described in the present disclosure asbeing in a normally open or normally closed condition, it iscontemplated that various other configurations could be utilized whileoperating within the scope of the present disclosure.

1. An engine control system for automatically starting an internalcombustion engine of outdoor power equipment, comprising: a manuallyactivated start button that generates a start signal upon activation; anenable device receptacle sized to receive a enable device; and acontroller that receives the start signal from the start button anddetects the presence or absence of the enable device in the enabledevice receptacle, wherein the controller activates a starter for theengine only when the enable device is in the enable device receptacleand the controller receives the start signal.
 2. The engine controlsystem of claim 1 further comprising an electric load coupled to thecontroller through a load relay, wherein the controller activates theload relay to provide power to the electric load only when the enabledevice is in the enable device receptacle and upon receipt of the startsignal.
 3. The engine control system of claim 2 wherein the start signalis continuously generated during continuous activation of the startbutton and the controller activates the starter only when the controllerreceives the start signal for longer than a minimum engagement period.4. The engine control system of claim 3 further comprising an ignitionshorting relay coupled to the controller, wherein the controlleractivates the ignition shorting relay to interrupt operation of theengine upon receipt of the start signal when the engine is running. 5.The engine control system of claim 1 wherein the outdoor power equipmentis a lawn tractor having a seat.
 6. The engine control system of claim 5further comprising a seat switch coupled to the controller, wherein thecontroller activates the starter only when the seat switch indicates thepresence of an operator on the seat.
 7. The engine control system ofclaim 1 wherein the start button includes an indicator that is activatedupon activation of the start button.
 8. The engine control system ofclaim 1 wherein the outdoor power equipment is a walk-behind mower.
 9. Amethod of automatically starting an engine of outdoor power equipment,the method comprising the steps of: providing a controller for theoutdoor power equipment; determining in the controller whether a enabledevice is in inserted into a enable device receptacle of the outdoorpower equipment; upon determining the enable device is inserted in theenable device receptacle, monitoring for the activation of a startbutton; determining when the start button is activated for longer than aminimum engagement period; and starting the engine only when the startbutton is activated for longer than the minimum engagement period andthe enable device is in the enable device receptacle.
 10. The method ofclaim 9 wherein the outdoor power equipment is a lawn tractor.
 11. Themethod of claim 10 further comprising the step of providing power to anelectric load of the lawn tractor after determining that the enabledevice is inserted into the enable device receptacle and the startbutton is activated.
 12. The method of claim 11 wherein power issupplied to the electric load when the start button is activated forless than the minimum engagement period.
 13. The method of claim 12further comprising the step of supplying power to the electric load foran auxiliary period after the start button is activated for less thanthe minimum engagement period.
 14. The method of claim 11 furthercomprising the step of detecting the presence of the operator in a seatof the lawn tractor, wherein the controller starts the engine only afterdetecting the presence of the operator.
 15. The method of claim 9further comprising the step of interrupting the operation of the engineupon activation of the start button after the engine is started.
 16. Themethod of claim 15 further comprising the step of supplying power to theelectric load for an auxiliary period following interruption of theoperation of the engine upon depression of the start button.
 17. A pushbutton starting system for a lawn tractor, comprising: a controllercoupled to a starter for an engine of the lawn tractor, wherein thecontroller selectively activates the starter to initiate operation ofthe engine; an enable device receptacle coupled to the controller andconfigured to receive a enable device, wherein the controller detectsthe presence of the enable device in the enable device receptacle; and astart button coupled to the controller, the start button generating astart signal received by the controller when the start button is in anactivated position, wherein the controller activates the starter upondetection of the presence of the enable device in the enable devicereceptacle and activation of the start button for longer than a minimumengagement period.
 18. The push button starting system of claim 17further comprising an electric load coupled to the controller through aload relay, wherein the controller activates the load relay to providepower to the electric load upon detection of the presence of the enabledevice in the enable device receptacle and activation of the startbutton.
 19. The push-button starting system of claim 18 wherein thecontroller activates the load relay to provide power to the electricload for an auxiliary period when the start button is activated for lessthan the minimum engagement period.
 20. The push button starting systemof claim 17 further comprising an ignition shorting relay coupled to thecontroller, wherein the controller activates the ignition shorting relayto interrupt operation of the engine upon receipt of the starting signalwhen the engine is running.
 21. The push button starting system of claim20 wherein the controller activates the load relay for the auxiliaryperiod upon activation of the ignition shorting relay such that theelectric load is energized for the auxiliary period after enginetermination.
 22. A method of automatically starting an engine of a lawntractor having a controller, the method comprising the steps of:determining in the controller whether a enable device is inserted into aenable device receptacle of the lawn tractor; upon determining thepresence of the enable device in the enable device receptacle,monitoring for the activation of a start button; upon activation of thestart button, providing power to an electric load of the lawn tractor;and upon detection of the activation of the start button for longer thana minimum engagement period, starting the engine of the lawn tractor.23. The method of claim 22 wherein power is supplied to the electricload for an auxiliary period when the start button is depressed for lessthan the minimum engagement period.
 24. The method of claim 22 furthercomprising the step of interrupting the operation of the engine uponactivation of the start button after the engine is started.